A bartender’s assistant has admitted killing a patron at a popular Times Square nightclub after Lil’ Kim’s birthday party there.

Syed Rahman will be sentenced to 20 years to life in prison next month for the 2008 murder of Ingrid Rivera, the Manhattan District Attorney’s office said.

Cops said Rahman, 24, helped get Rivera back into the since shuttered Spotlight Live after she’d been tossed out for being too drunk. He lured her up to the roof, and then “savagely and viciously” bludgeoned her with a steel pipe after she rejected his advances.

He then slashed her throat and left her lying in a pool of blood on a deserted area of the club’s roof, authorities said. Her body was discovered two days later.